1. Field of the Invention
The present invention relates to a heat dissipation fan, and more particularly to a small direct current heat dissipation fan having a locking plate.
2. Description of Related Art
A conventional heat dissipation fan in accordance with the prior art shown in FIG. 4 and FIG. 5 comprises a heat dissipation fan blade (60), a bearing (61), a stator (63) with a circuit board (62) and a casing (64). The heat dissipation fan blade (60) has an shaft (601) extending therefrom. The shaft (601) has a free end that is cone-shaped and contains a groove (602) to receive a locking ring (50). The casing (64) includes a collar (641) to hold the stator (63) in place, and the collar (641) contains a recess (642) to receive the bearing (61). The recess (642) has a through hole (643) to allow the shaft (601) to extend through. The locking ring (50) contains a hole (51) that has a diameter corresponding with that of the groove (602). The locking ring (50) further contains a slit (52) extending out from the hole (51).
To assemble the heat dissipation fan, the stator (63) and the circuit board (62) are placed around the collar (641) of the casing (64), and the bearing (61) is pressed into the recess (642) of the collar (641). The shaft (601) of the heat dissipation fan blade (60) is locked into the bearing (61) by the locking ring (50) that is clipped into the groove (602) after the shaft extends through the bearing (61) and the through hole (643) of the recess (642).
A worker needs a tool to press the locking ring (50) into the groove (602) of the shaft (601) when assembling the heat dissipation fan. Since the locking ring (50) has only one slit (52), the slit (52) will be opened widely when pressed over the free end of the shaft (601). This heat dissipation fan is a small device with small parts, and the locking ring (50) must be mounted deep in the collar (641) of the casing (64). Consequently, a worker needs to use a special tool to press the locking ring (50) into the groove (602) of the shaft (601). It will be tedious for the worker and reduce output efficiency.
The groove (602) in the shaft (601) extends below the through hole (643) of the recess (642). Therefore, the blade (60) easily falls down and abuts the top portion of the bearing (61). This will cause improper chafing between the blade (60) and bearing (61). The chafing will damage the blade (60) and bearing (61) and further reduce the life of the heat dissipation fan.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional